Aircraft doors have locking mechanisms including a toggle lever arrangement for achieving a positive locking in the closed position. It is also known to provide aircraft doors with a compartment containing an emergency exit chute. A control lever is provided for making the chute ready for use when the door has been closed to bring the chute into a stand-by condition or state. It is also standard practice that two different levers must be operated for closing the door in accordance with safety regulations in order to avoid accidents caused by improperly closed doors or by a door that has not been properly latched in its closed position. Most recent safety regulations suggest and require that doors for pressurized aircraft cabins are equipped with means for testing the complete and safe latching of any aircraft door.
One such means for testing could, for example, comprise a venting device arranged in such a manner that it prevents the pressurization of the aircraft cabin when the door is not properly or completely latched. Thus, an indication of an insufficiently or improperly locked door would be provided by the fact that the aircraft cabin cannot be pressurized. However, such a solution to the problem of providing an indication of an improperly locked aircraft door is involved and hence expensive since it requires means for sensing cabin pressure in response to a properly closed door. The additional equipment needed for this purpose would add to the aircraft weight and to its costs. Another disadvantage of such a solution is seen in that a certain length of time would have to pass after starting the cabin pressurization before an improperly closed or improperly locked door could be discovered. Thus, steps to properly close the door could only be taken after such discovery and these delays are undesirable.